Objective

Interpreting lateral spread response (LSR) during microvascular decompression (MVD) for hemifacial spasm (HFS) is difficult when LSRs observed in different muscles do not match. We aimed to analyze LSR patterns recorded in both the orbicularis oris (oris) and mentalis muscles and their relationships with clinical outcomes.

Methods

The data of 1288 HFS patients who underwent MVD between 2015 and 2018 were retrospectively reviewed. LSR was recorded in the oris and mentalis muscles through centrifugal stimulation of the temporal branch of the facial nerve after preoperative mapping. The disappearance of LSR following surgery, clinical outcomes, and the characteristics of LSR in oris were analyzed.

Results

After surgery, LSR remained in 100 (7.7%) and 279 (21.6%) of the mentalis and oris muscles, respectively. The postoperative outcome correlated with LSR disappearance in the mentalis, not with that in the oris.

Conclusion

LSR patterns differed in each muscle and may not be correlated with clinical outcomes. LSR in the mentalis and oris muscles should be interpreted differently.

Significance

We describe a monitoring protocol characterized by preoperative facial nerve mapping, antidromic stimulation, and recording from multiple muscles. We analyze differences in LSRs in the mentalis and oris muscles and suggest technical points for interpretation.

中文翻译：

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面肌痉挛微血管减压术中不同面部肌肉的横向扩散反应

客观的

当在不同肌肉中观察到的 LSR 不匹配时，解释面肌痉挛 (HFS) 微血管减压 (MVD) 期间的横向扩散反应 (LSR) 是困难的。我们旨在分析在口轮匝肌 (oris) 和颏肌中记录的 LSR 模式及其与临床结果的关系。

方法

回顾性分析了 2015 年至 2018 年间接受 MVD 的 1288 例 HFS 患者的数据。在术前标测后，通过面神经颞支的离心刺激在口肌和颏肌中记录 LSR。分析手术后LSR的消失、临床结果和口腔LSR的特点。

结果

手术后，LSR 分别保留在 100 (7.7%) 和 279 (21.6%) 的颏肌和口肌中。术后结果与颏部的 LSR 消失相关，而与口部的 LSR 消失无关。

结论

每块肌肉的 LSR 模式不同，可能与临床结果无关。应以不同方式解释颏肌和口肌中的 LSR。

意义

我们描述了一种以术前面部神经映射、逆向刺激和多块肌肉记录为特征的监测协议。我们分析了精神肌和口肌中 LSR 的差异，并提出了解释的技术要点。